Featured Research

from universities, journals, and other organizations

Much of early methane rise can be attributed to spreading of northern peatlands

Date:
January 17, 2010
Source:
University of Helsinki
Summary:
The surprising increase in methane concentrations millennia ago, identified in continental glacier studies, has puzzled researchers for a long time. According to a strong theory, this would have resulted from the commencement of rice cultivation in East Asia. However, a study by researchers in Finland shows that the massive expanse of the northern peatlands occurred around 5000 years ago, coincident with rising atmospheric methane levels.

The surprising increase in methane concentrations millennia ago, identified in continental glacier studies, has puzzled researchers for a long time. According to a strong theory, this would have resulted from the commencement of rice cultivation in East Asia. However, a study conducted at the University of Helsinki's Department of Environmental Sciences and the Department of Geosciences and Geography shows that the massive expanse of the northern peatlands occurred around 5000 years ago, coincident with rising atmospheric methane levels.

Related Articles


After water vapour and carbon dioxide, methane is the most significant greenhouse gas, resulting in about one fifth of atmospheric warming caused by humans. Methane emissions are mainly created by peatlands, animal husbandry, rice cultivation, landfill sites, fossil fuel production and biomass combustion.

Northern peatlands are immense sources of methane, but previous studies have argued them to have been established almost immediately after the Ice Age ended. Consequently, they could not explain the increase of methane, dated to have commenced thousands of years later, since the methane emissions of peatlands decrease as they age.

William Ruddiman, Professor Emeritus in environmental sciences at the University of Virginia, has presented a widely published theory according to which humanity started to affect the climate thousands of years ago, not just since the start of the industrial revolution. According to the theory, rice cultivation, commenced in East Asia already over 5,000 years ago, caused the declining methane amounts to again increase, which contributed to preventing the next ice age.

The timeframe of the spread of peatlands matches the increase in methane levels

The new study, conducted under the supervision of Professor Atte Korhola, explains the emergence of the peatlands in the northern hemisphere, and their development history, in a new way. The researchers compiled an extensive radiocarbon dating database concerning the bottom peat in peatlands. Based on over 3,000 dates, their statistical and location information-based analysis, it was identified that the expansion of northern peatlands significantly accelerated about 5,000 years ago. At the same time, the methane content in the atmosphere started to increase.

Peatland expansion resulted in the emergence of millions of square kilometres of young peatlands of the mineretrophic fen type, and they puffed large amounts of methane gas in to the air as the organic matter rotted. According to the study, the early increase in methane levels was mainly caused by natural reasons, and human operations are not necessarily required to explain it.

The expansion of peatlands was triggered by the climate turning moister and cooler, which caused the groundwater levels to rise, while accelerating peat build-up and growth. A similar methane peak may also emerge in the future if precipitation in the arctic areas increases as forecasted.

The study was published last week in the Quaternary Science Reviews series, and the study was conducted by Atte Korhola, Professor; Meri Ruppel, M.A.; and the docents Minna Väliranta, Tarmo Virtanen and Jan Weckström from the University of Helsinki's Environmental Change Research Unit (ECRU) and Heikki Seppä, Professor in the Department of Geosciences and Geography at the University of Helsinki.


Story Source:

The above story is based on materials provided by University of Helsinki. Note: Materials may be edited for content and length.


Journal Reference:

  1. Korhola et al. The importance of northern peatland expansion to the late-Holocene rise of atmospheric methane. Quaternary Science Reviews, 2010; DOI: 10.1016/j.quascirev.2009.12.010

Cite This Page:

University of Helsinki. "Much of early methane rise can be attributed to spreading of northern peatlands." ScienceDaily. ScienceDaily, 17 January 2010. <www.sciencedaily.com/releases/2010/01/100114081543.htm>.
University of Helsinki. (2010, January 17). Much of early methane rise can be attributed to spreading of northern peatlands. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2010/01/100114081543.htm
University of Helsinki. "Much of early methane rise can be attributed to spreading of northern peatlands." ScienceDaily. www.sciencedaily.com/releases/2010/01/100114081543.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Scientists Find Invisible Space Shield Protecting Earth

Scientists Find Invisible Space Shield Protecting Earth

Newsy (Nov. 27, 2014) — An invisible barrier is keeping dangerous super fast electrons from interfering with our atmosphere, but scientists aren't entirely sure how. Video provided by Newsy
Powered by NewsLook.com
Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) — Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Blu-Ray Discs Getting Second Run As Solar Panels

Blu-Ray Discs Getting Second Run As Solar Panels

Newsy (Nov. 26, 2014) — Researchers at Northwestern University are repurposing Blu-ray movies for better solar panel technology thanks to the discs' internal structures. Video provided by Newsy
Powered by NewsLook.com
Antarctic Sea Ice Mystery Thickens... Literally

Antarctic Sea Ice Mystery Thickens... Literally

Newsy (Nov. 25, 2014) — Antarctic sea ice isn't only expanding, it's thicker than previously thought, and scientists aren't sure exactly why. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins